Lighting devices for having specific lighting properties are known in the art. US2016223146, for instance, describes light sources that emit light having enhanced color spectrum characteristics. A color metric called the Lighting Preference Index (LPI) is described that enables quantitative optimization of color preference by tailoring the spectral power distribution of the light source. A lamp includes at least one blue light source having peak wavelength in the range of about 400 nanometer (nm) to about 460 nm, at least one green or yellow-green light source having peak wavelength in the range of about 500 nm to about 580 nm, and at least one red light source having peak wavelength in the range of about 600 nm to about 680 nm, wherein the lamp has an LPI of at least 120. The formula for LPI is based on an observer set within the age range of 21 to 27 years, with a gender distribution of 58% male and 42% female, a race distribution of 92% Caucasian and 8% Asian, and a geographical distribution within North America.